Process and apparatus for printing periodicals and the like

Abstract

A method for imaging film with color separations and text which eliminates manual stripping and the use of mylar carriers. Color separation data from a color scanner is stored digitally on a computer. Text is input directly into the computer. The data for the images and text is manipulated digitally to compose a page layout. The computer then instructs an image setter to image the complete, composed page onto four pieces of film in the four color printing colors--cyan, magenta, yellow and black. The imaged film is used to make lithographic printing plates for color printing. The image setter used in the method includes a specially pinned drum having pins corresponding to pins used during imposition. Blank film has prepunched holes corresponding to the pins on the pinned drum so that the imaged film comes off of the drum with images and text in position and register relative to the pin holes. The labor intensive steps of manually stripping film onto mylar carriers is eliminated.

I claim: 
     
       1. An imaging drum for use in an image setting device, said drum comprising: a cylindrical drum body defining an outer peripheral surface;   means for mounting said cylindrical drum body for rotation about an axis centrally positioned with respect to said peripheral surface of said drum body;   a plurality of single-page film mounting areas disposed on said peripheral surface of said drum body, each film mounting area being adapted to receive a single-page sheet of film,   a plurality of spaced apart pins projecting radially outward from said peripheral surface of said drum body at each film mounting area such that a plurality of pins is adapted to mount each single-page sheet of film; and   a plurality of vacuum channels defined in said peripheral surface of said drum body such that a set of vacuum channels are provided at each film mounting area to securely hold the single-page sheets of film to said drum.   
     
     
       2. The imaging drum of claim 1, in which said drum body includes at least one film mounting area defined on a first arcuate segment of said peripheral surface and at least one film mounting area defined on a second arcuate segment of said peripheral surface, wherein said first and second arcuate segments are offset from one another in the direction of rotation of said drum body. 
     
     
       3. The imaging drum of claim 2, in which a plurality of film mounting areas are defined in each arcuate segment of said peripheral surface of said drum body. 
     
     
       4. The imaging drum of claim 2, in which each of said film mounting areas defines a leading edge and a trailing edge with respect to the rotation of said drum body, and in which each mounting area includes a first pin located adjacent the leading edge and a second pin located adjacent the trailing edge. 
     
     
       5. The imaging drum of claim 4, herein each said pin adjacent said leading edge of each film mounting area is proximate to a pin adjacent said trailing edge of another film mounting area. 
     
     
       6. The imaging drum of claim 1, in which each of said film mounting areas defines a leading edge and a trailing edge with respect to the rotation of said drum body, wherein each mounting area includes a first pin located adjacent the leading edge and a second pin located adjacent the trailing edge, and wherein each said pin adjacent said leading edge of each film mounting area is proximate to a pin adjacent said trailing edge of another film mounting area. 
     
     
       7. The imaging drum of claim 1, in which said peripheral surface of said drum body defines a plurality of arcuate segments, said arcuate segments being arranged in a seriatim manner with respect to the direction of rotation of said drum body, wherein each of said arcuate segments includes at least one film mounting area. 
     
     
       8. The imaging drum of claim 7, in which a plurality of film mounting areas are disposed in each of said arcuate segments of said drum body peripheral surface. 
     
     
       9. An image setting device comprising: a drum including:   a cylindrical drum body defining an outer peripheral surface;   means for mounting said cylindrical drum for rotation about an axis centrally positioned with respect to said peripheral surface of said drum body;   a plurality of single-page film mounting areas disposed on said peripheral surface of said drum body, each film mounting area being adapted to receive a single-page sheet of film,   a plurality of spaced apart pins projecting radially outward from said peripheral surface of said drum body at each film mounting area such that a plurality of pins is adapted to mount each single-page sheet of film; and   a plurality of vacuum channels defined in said peripheral surface of said drum body such that a set of vacuum channels are provided at each film mounting area to securely hold the single-page sheets of film to said drum;   means for rotating said drum;   means for creating a vacuum in said vacuum channels; and   means for imaging the single-page sheets of film mounted on said drum.   
     
     
       10. The image setting device of claim 9, in which each of said film mounting areas of said drum defines a leading edge and a trailing edge with respect to the rotation of said drum body, wherein each mounting area includes a first pin located adjacent the leading edge and a second pin located adjacent the trailing edge, and wherein each said pin adjacent said leading edge of each film mounting area is proximate to a pin adjacent said trailing edge of another film mounting area. 
     
     
       11. The image setting device of claim 9, in which said peripheral surface of said drum body defines a plurality of arcuate segments, said arcuate segments being arranged in a seriatim manner with respect to the direction of rotation of said drum body, wherein each of said arcuate segments includes at least one film mounting area. 
     
     
       12. The image setting device of claim 11, which a plurality of film mounting areas on said drum are disposed in each of said arcuate segments of said drum body peripheral surface.